Elements for labyrinth seals



May 12, 1959 i w, HEARD 2,886,351

ELEMENTS FOR LABYRINTH SEALS Filed Jan. 3, 1956 2 Sheets-Sheet 1 INVNTOK WILLIAM 1.. saw

A-rroryyevs.

May 12, 1959 w. L. HEARD 2,386,351

' ELEMENTS FOR LABYRINTH SEALS Filed Jan. 5, 1956 2 Sheets- Sheet 2 mvgnrrob WILLIAM L. Henna H 2,886,351 ELEMENTS For: LABYRINTH SEALS William Lane Heard, Milton, Ontario, Canada, assignor to Orenda Engines Limited, Malton, Ontario, 'Canada' January 3, 1956, Serial No. 556,919 8 Claims or. 286-) This invention I ticularly concerned with a labyrinth seal element WhlCh 1s to be engaged in a bore of one structural member form- Application ing part of the seal for co-action with a shaft forming another structural member of the seal or, conversely, en'- gaged on the said shaft for co-action with the wall of the said bore. I

It has previously been proposed to form a labyrinth seal from a plurality of annular labyrinth seal elements which are held spaced and accurately aligned in a bore United States Patent relates to a labyrinth seal, and is p-ar-' 2,886,351 Patented May 12, 19 59 Ice the following specification, taken in conjunction with the accompanying drawings, in which like reference. characters indicate corresponding parts throughout the severali views, and in which:

Figure 1 is a perspective view of a labyrinth seal element according to the invention, the labyrinth seal ele- 'ment being of preferred construction and for the engagethe drawing showing a plurality of labyrinth seal eleor on a shaft by interposed spacers. In such constructions the sealing elements and spacers are embedded in grooves,

or they area press fit in the bore or on the shaft and are brazed in position to form an integral unit. assembly of the seal elements and spacers in or on the associated structural part is a very delicate and tedious operation involving'the use of highly skilled labour and expensive jigs. Also, difiiculty has been experienced in satisfactorily brazing the assembly due to the fact that the seal elements and spacers have to be held in their correct position by jigs when the brazing operation is being carried out. I

one object of this invention is to provide an element for a labyrinth seal which is simple and inexpensive to manufacture, and which can be assembled on to a supporting component using simple and inexpensive jigs.

Another object is toprovide-alabyrinth seal element whichhasa form or configuration rendering the use of jigs unneces'sary for holding the element in position while thebrazing operation is being carried out.

A further object is to provide a labyrinth seal element which is self-supporting in an appropriate bore or on a shaft of appropriate diameter.

A still further object is} to provide a labyrinth seal element having an integral s'pacer. I

Ajstill further object is fto provide a labyrinth seal which is of reduced weight-as compared with the previously proposed constructions.

Accordingto one featii'reof the invention, an element for a labyrinth seal comprises an annulus for co-action at one of its peripheries with a structural member forming' part of the labyrinth seal, and means integral with the'lisaid annulus forengagement with another structural member of the labyrinth seal, the said means extending Thements according to Figure'l in position in a bore and co-acting with a shaft;

Figure 6 is a fragmentary perspective view of another embodiment of the labyrinth seal element of the invention, the element being for engagement in a bore and from theother periphery of the, said annulus in a direction substantially parallel to the axis of the said annulus to provide an ab-u'tment for afurther labyrinth seal ele-' ment-to be engaged with said other structural member.

According to a further feature of the invention, a labyn'nth seal comprises in combination a first structural' member having a bore, asecond structural member movable relatively to said first'member within said bore, and a plurality of sealing elements positioned in said bore between said members, each of said elements including an annulus force-action at'on'e of its peripheries with one of said structural members and means' integral with said annulus and for engagement with the other structurah'member, said'means extending from the other periphery of saidannulus' in a direction substantially parallel to the axis of said annulus to provide an abutment for a further labyrinth seal element engaged with said other structural member.

'lhe foregoing and still furtherobjects and advantages of the invention will become apparent from, a study of co-action with a shaft; 7. Figure 7 is a section on the line 77 of Figure 6; Figure 8 is a fragmentary perspective view of an embodiment of the invention similar to Figure 6, but showing a labyrinth seal element constructed for engagement with a shaft and for co-action with the wall of a bore; Figure 9 is a section on'the line 99 of Figure 8; Figure 10 is a fragmentary perspective view of a further embodiment of the labyrinth seal element of the invention, the element being for engagment in a bore and co-action with a shaft;

Figure 11 is a section on the line 1111 of Figure 10; Figure 12 is a fragmentary perspective view of an embodiment of the invention similar to Figure 10, but showing a labyrinth seal element constructed for en-. gagement with a shaft and for co-action with the Wa11g' of a bore; and v Figure 13 is a section on the line 13 13 of Figure 12. Referring to Figures 1. and 2, the labyrinth sealtelement is formed as a stamping or pressing from thin sheet metal,

for example, stainless steel, and includes an annulus 10, the internal periphery of Which is to co-act with the periphery of a shaft, and a flange indicated by the arrow 11. The flange, as will be seen from the drawings, is

' bers in one of which a plurality of the labyrinth seal elements shown in Figure 1 are engaged.

One of the structural members is a shaft 15 which is mounted in bearings 16 for rotation co-axially within a bore 17 of the other structural member 18. As will be seen, the bearing 16 abuts a shoulder 19 of the structural member 18 and is held in position by an externally threaded ring 20. The labyrinth seal elements 10, 11 are engaged in the bore 17 for the inner periphery of their annulus 10 to co-act with the periphery of the shaft 15.

' For assembling the seal, the structural member 18 (without the shaft 15 and bearings 16) has a plug (not shown) inserted in the right-hand end of its bore 17 to form an end stop and abutment and a labyrinth sealelement 10, 11 is forced into the left-hand end of the bore,

, with the face of the annulus remote from the flange pre The pitch circle of the fingers 13 of each of the labyrinth seal elements is of greater diameter than the bore 17, and the diameter of the outer periphery of the annulus:- IQ is, substantially the, same .as that. of, the; bore "17,

elementis formed, andt-thetinherent resilience engendered hen. the, element-is forced-into the bore the g I 13 ,are foreed,radia1 ly inwardly.. r .T hus, owing to the resiliency of the metal from" whic'hi thel labyrinth seal the flange 11d is formed by fingers .12dwhichparearranged by the partieular form of the, flangegll', which concerin a peripheral series integralwith the annulus 10d at its outer periphery, and which have turned inwardly at their extremities remote from the annulus 10:1 to provide abutment surfaces 25. L

Figures 12 and 13.show a labyrinth seal elementnac cording to the modifications of Figures 10 and '11 is to be positioned on a shaft, the flange, 11 being formed of fingers 12e having outwardlyturned extensions '26, the fingers 12a being integral-with the annulus 10e at'itsinnerperiphery. t v. .7 a a,

.' In :the constructions of Figures: 1,:v 6' andslOnaboV'ecdeaiscribed the'fianges 11, 11b, lldcare'of 'grea'ter'diameteri at theirgedger remote from-theannulus'; than they rare at their edges integral with the annulus -soihatzthefingersn can resiliently engage the, wallizofsan appropriate: bor when the labyrinth seal is assembled. Conversely;;..the't2 edges ofgtheflanges 11a, 11c, 11d remote fromrtheannulus axially locating the annulus 10 of then subsequently in-,, serted element, as is indicated in Figure 2'. This procedure,

repeated until the requisite numbenofelements have been positioned in the bore, after which the plugis removed aridthe assembled series of latjyrinthseal elements are.

braied'to the inner wall of the bore. his unnecessary to support the labyrinthseal elements during the brazing operation, as theresiliency of the flangesll'holds, them aceurately in position. Also; the undulationsin the flanges 11 provide, reservoirs in which the brazing metal is held by capillary action and/ or by surface tension oi the molten ,metal tthus' forming a most effi'cient brazed joint between the elements andjhewall of the boreg If desired; the pockets formed the, undulations canbe packed with asuitable fluir and powdered brazing metal before'the seals are insertedinto the bores.

In some cases it may be desired to positionhthe l'abyrinth seal-element on the shaft, so that the external periph cry of the annulus co-acts with the wall of the bore, Such an 'element-is-shown in'Figures 3' and 4, where the fingers are arranged-on a circle of smaller diameter thanthednnbm: periphery of the annulus so that the fingers will resilientlyzw engage;-the-;periphery of a'shaft with ,whichQ-they are:- engaged. v

Ibwillbe seen that bythe inventionalabyr nthaseah I is provided which is of simple; construction, whichisjlight in, wei-ght andwhich, by virtue of its integralfiange avoids the: weight penalty imposed by the useof separatevv a; spacers; Also, thelabyrinthseal elementis of alform which is particularly adapted for brazing" to an appropri ate. supporting structural ,member,, andis self suppqrtin in or-on an, appropriate structural membenwhiledheibraz ing; operation isbeing carried'out.

What I claim as my invention is: g ,laAn element for a labyrinth seal, comprising a continuous, ,imperforate annulus stor coaction at rone: of its e peripheries wtih one structural member formingpart'ofwavg labyrinthseal and adapted to be engaged -atits othcl' periphery with another structuraltmember 9fthe labyrinth seal, circumferentially-spacedr,fingers formed -;integral]y; with said. annulus at its said other periphery and exten ,7 ing from a radial, face thereof in a direction substantially'.;, parallelto but ata small angle to-the axis of the annulus forthelfingers to extend away fromsaid tone structurah member and whereby thefingers mayyresiliently engage Ha -will{resiliently-grip the s hait 'to' locate theelement 1 prior to -;the brazing operation- ,The series of elements is assembled and brazed as previously described.

Although the labyrinth seal elements above described are-of-the' preferred construction according to the invention,-;various modifications may be made without departing from the spirit'of the invention.- The essential features f the'invention are that the flange shall resiliently engage the supporting member to locate the labyrinth'seal element, and that the freeedgeof the flangeshall'provide an-abutment for a subsequent element to be engaged with the supporting member. v

Figures6 to 13 show various modificationsof the labyrinth seal element according to' the invention, and. are given by way of example and are not vto be, considered exhaustive of the various forms, or combinationsof forms the'tfian'ge may take.

In -Figures 6 and 7, the flange ll'bis formed by a plurality of fingers 12b which are arranged in a series integral withthe outerperiphery of the annulus 1012. Each ofthe-fingerslZb is bowed-in an axialrdirection to increase their-resiliency and to provide anabutment as i mentioned hereinabove.

Figures-8 and 9 show a modification-of Figures 6 and 7, the labyrinth seal element of Figures .Sand 9 being;

Figures 10 and 11 show a further modification, in which J l'abyrinth sealand adapted tot bewengaged-at,-itS ME;

I direction substantially'parallel-g to but .at a small angle ge series being positioned between two fingers of first with the adjacent fingers of the firstseries, and webs free edge of the'flangefconstitutingaan,abutment,.ofqnathe annulus than the thickness of the material from v thesaidanother structural vmember;each fingervbeing formed at its free end to provideanabutment, oil-ma terially greaterextent measured in a directioii radially of the annulus than the thickness of the material; from the finger is formed, for a further labyrinth sealelernent to be mounted on the said another structural members,

2.f,-A'1i element for. a labyrinth seal, comprising, 3. 0011 tinuous, imperforate annulus. tor coaction at oneaofiaits peripheries. with one structuraLmember forming partofi periphery with anothertstructuralmember of the labyrinth seal,j a first series of-.circumferentia1ly spacedfingers formed integrally withsaid: annulus at its saidgth periphery and extending from a radial faceathereof in a thejaxis of the annulus for. the fingers to extend away fromfsaid one structural member. and whereby the fingers may resiliently engage the said anotherstructural rneml ae a second series of circumferentiallyrspaeed fin'gers integral 7 1 uwith s'aid annulus at itssaid other periphery. and extending fromj said radial ,fa'c'e thereof, each finger of theilsecond series" and extending toward s'isaid one structural'memher for'the, fingers of the second series to defineasmallang ing a transition between adjacent ones ofhthe' fingers provide a continuous peripherally. undulated -flange, the

terially greater extent measured'in' a direction radially of theflaiigeis formed, for a further, labyhnth sealelementgr to be mounted on thesaid another structural member.

3. An element for a labyrinth seal, comprising a continuous, imperforate annulus for coaction at one of its peripheries with one structural member forming part of a labyrinth seal and adapted to be engaged at its other periphery with another structural member of the labyrinth seal, circumferentially-spaced fingers formed integrally with said annulus at its said other periphery and extending from a radial face thereof in a direction substantially parallel to but at a small angle to the axis of the annulus for the fingers to extend away from said one structural member and whereby the fingers may resiliently engage the said another structural member, each finger being bowed in a direction transversely of the finger for the free end of the finger to constitute an abutment, of materially greater extent measured in a direction radially of the annulus than the thickness of thelmaterial from which the finger is formed, for a further labyrinth seal element to be mounted on the said another structural member.

4. An element for a labyrinth seal, comprising a con tinuous, imperforate annulus for coaction at one of its peripheries with one structural member forming part of a labyrinth seal and adapted to be engaged at its other periphery with another structural member of the labyrinth seal, circumferentially-spaced fingers formed integrally with said annulus at its said other periphery and extending from a radial face thereof in a direction substantially parallel to but at a small angle to the axis of the annulus for the fingers to extend away from said one structural member and whereby the fingers may resiliently engage the said another structural member, each finger being bent at its free end to provide a discontinuous flange lying in a plane substantially parallel to the said radial face and directed towards said one structural member for the free ends of the fingers to constitute an abutment, of materially greater extent measured in a direction radially of the annulus than the thickness of the material from which the finger is formed, for a further labyrinth seal element to be mounted on the said another structural member.

5. A labyrinth seal, comprising in combination a first structural member having a bore, a second structural member movable relative to the first member within said bore, and a plurality of labyrinth seal elements positioned in said bore between said members, each of said elements including a continuous, imperforate annulus for coacting at one of its peripheries with one of the structural members and adapted to be engaged at its other periphery with the other structural member, circumferentially-spaced fingers formed integrally with said annulus at its said other periphery and extending from a radial face thereof in a direction substantially parallel to but at a small angle to the axis of the annulus for the fingers to extend away from said one structural member and whereby the fingers may resiliently engage said other structural member, each finger being formed at its free end to provide an abutment, of materially greater extent measured in a direction radially of the annulus than the thickness of the material from which the finger is formed, for a further labyrinth seal element to be mounted on the said other structural member.

6. A labyrinth seal, comprising in combination a first structural member having a bore, a second structural member movable relative to said first member within said bore, and a plurality of labyrinth seal element positioned within said bore between said members, each of said elements including a continuous, imperforate annulus for coaction at one of its peripheries with one of the structural members and adapted to be engaged at its other periphery with the other structural member, a first series of circumferentially-spaced fingers formed integrally with said annulus at its said other periphery and extending from a radial face thereof in a direction substantially parallel to but at a small angle to the axis of the annulus for the fingers to extend away from said one structural member and whereby the fingers may resiliently engage said other structural member, a second series of circumferentially-spaced fingers integral with said annulus at its other periphery and extending from said radial face thereof, each finger of the second series being positioned between two fingers of the first series and extending towards said one structural member for the fingers of the second series to define a small angle with the adjacent fingers of the first series, and webs forming a transition between adjacent ones of the fingers to provide a continuous peripherally undulated flange, the free edge of the flange constituting an abutment, of greater extent measured in a direction radially of the annulus than the thickness of the material from which the flange is formed, for a further labyrinth seal element to be mounted on the said another structural member.

7. A labyrinth seal, comprising in combination a first structural member having a bore, a second structural member movable relative to said first member within said bore, and a plurality of labyrinth seal elements positioned within said bore between said members, each of said elements including a continuous, imperforate annulus for coaction at one of its peripheries with one of the structural members and adapted to be engaged at its outer periphery with the other structural member, circumferentially-spaced fingers formed integrally with said annulus at its said other periphery and extending from a radial face thereof in a direction substantially parallel to but at a small angle to the axis of the annulus for the fingers to extend away from said one structural member and whereby the fingers may resiliently engage said other structural member, each finger being bowed in a direction transversely of the finger for the free end of the finger to constitute an abutment, of materially greater extent measured in a direction radially of the annulus than the thickness of the material from which the finger is formed, for a further labyrinth seal element to be mounted on the said other structural member.

8. A labyrinth seal, comprising in combination a first structural member having a bore, a second structural member movable relative to said first member within said bore, and a plurality of labyrinth seal elements positioned within said bore between said members, each of said elements including a continuous, imperforate annulus for coaction at one of its peripheries with one of the structural members and adapted to be engaged at its outer periphery with the other structural member, circumferentially-spaced fingers formed integrally with said annulus at its said other periphery and extending from a radial face thereof in a direction substantially parallel to but at a small angle to the axis of the annulus for the fingers to extend away from said one structural member and whereby the fingers may resiliently engage said other structural member, each finger being bent at its free end to provide a discontinuous flange lying in a plane substantially parallel to the said radial face and directed towards said one structural member for the free end of the finger to constitute an abutment, of materially greater extent measured in a direction radially of the annulus than the thickness of the material from which the finger is formed, for a further labyrinth seal element to be mounted on the said other structural member.

References Cited in the file of this patent UNITED STATES PATENTS 907,808 Jebsen Dec. 29, 1908 1,641,749 Enders Sept. 6, 1927 1,817,776 Sipe Aug. 4, 1931 FOREIGN PATENTS 92,994 Austria June 11, 1923 506,868 Canada Oct. 26, 1954 566,812 Great Britain Jan. 16, 1945 

